import sun.font.CreatedFontTracker;

public class Test {
    public static void main(String[] args) {
        int a = 1;
        int b = 2;
        System.out.println(10 && 20); //error
    }



    public static void main11(String[] args) {
        int a = 10;
        int b = 20;
// 注意：在Java中 = 表示赋值，要与数学中的含义区分
//     在Java中 == 表示相等
        System.out.println(a == b);
        System.out.println(a != b);
        System.out.println(a < b);
        System.out.println(a > b);
        System.out.println(a <= b);
        System.out.println(a >= b);
    }

    public static void main10(String[] args) {
        int a =10;
        int b = a++; //等价于b = a; a = a + 1;
        int c = ++a; //等价于a = a + 1; c = a;
    }

    public static void main9(String[] args) {
        short a = 10;
        a++;
        int b = 20;
        b++;
        System.out.println(a);
        System.out.println(b);
    }


    public static void main8(String[] args) {
        byte sh = 2;
        sh += 127;
        System.out.println(sh);
    }


    public static void main7(String[] args) {
        System.out.println(10%3);
        System.out.println(10%-3);
        System.out.println(-10%3);
        System.out.println(-10%-3);

        System.out.println(11.5%2.5);  //在Java里面是允许的
    }




    public static void main6(String[] args) {
        String str = "12.5f";
        float f = Float.valueOf(str);
        System.out.println(f);
    }



    public static void main5(String[] args) {
        String str = "123456";
        int a = Integer.valueOf(str);
        System.out.println(a+1);
    }



    public static void main4(String[] args) {
        int a = 12345;
        String aa = a+"";
        System.out.println(aa);
        System.out.println("----->"+aa);
    }




    public static void main3(String[] args) {
        int a = 12345;
        String str = String.valueOf(a);
        System.out.println(str);

        float f = 12.5f;
        String ret = String.valueOf(f);
        System.out.println(ret);
    }


    public static void main2(String[] args) {
        String str1 = "hello";
        String str2 = "world";
        System.out.println(str1+str2);
        int a = 10;
        int b = 20;

        System.out.println(a+b+"是a + b的值 ");
    }





    public static void main1(String[] args) {
        int a = 10;



        String str = "hello";
        System.out.println(str);
    }



//    public static void main(String[] args) {
//        char c = 0;
//        int a = 10000;
//        c = (char)a;
//    }
}
